Threading machine



March 29,1932. E w. MlKAELSON 1,351,357

THREADING MACHINE Original Filed Dec 18. 1928 3 Sheets-Sheet 1 March 1932- E. RMKAELS N 1,851,367

THREADING MACHINE Original Filed Dec. 18, 1928 3 Sheets-Sheet 2 March 29, 1932. Y w M|KAE4LSOIN 1,851,367

THREADING MACHINE Origihal Filed Decv 18, 1928 3 SheetsSheet '3 Patented @Mar. 29, 1932 ,ERIK W. .MIKAELSON, OF H EASTON, PENNSYLYANIA, ASSIGNOR TO TREADWELL ENG NEE ING COMIEANY, OFQEASTI'OIT, PENNSYLYAN A,- A.GORPOBAEIONiGE' IBENN SYLVANIA THREADING,MACHINE Original application'filed December 18, 1928, Serial No. 326,866. Divided and this application filed October 28, 1930. Serial No. 491,752.

I'lhis invention relates to threading machines, and has for its ob ectithe provision of novel means forishifting the thread cutting elements into and out of engagement -with the. stock on which the thread is cut. 'uAlthou'gh the means disclosednhereinfor accomplishing this function, is of. general application andmay be used with any type of threading machine, it is shown asapplied to a combined cutting and threading machine of the type described and claimed in my I oopending application, 'Ser. No. 326,866,.filed December 18, 1928, ofiwhich this application is a division.

It is a featureof the present invention-to -.provide-means whereby the extent of move- 'ment ofthe cutting elements into-ithreadcutting position may be accurately determined and readily. adjusted, and whereby the cutting elements may be firmly retained inthe 1 proper cutting. relation withthe. stock regard. less of objectionableclearance inctherelativa. ly moving'parts: due to-temperature changes and wear. I

A further object ofthe invention is the provisionof meansr'for taking up. wear in themoving parts which support the thread cutting elements, andufo'r ensuring accurate alignment of such partsnto avoid incorrect cutting and mutilation. of the threads.

Other objects andfeatures of thepresent invention will .be apparent from the following description taken in connectionwiththe accom )an in drawin s .in which- Figure 1-is an elevation'of a threading ma- :chine embodyingv my. invention;

Figure 2 is an end view. ofthe mechanism for: supporting and ,shiftingithe thread cutting elements intouand out of engagement with the-stock, the'elementsbelng shown in stock engaging or operative; position Figure 3isa. View similar toFigure 2 showing thethreadcutting elements-in disengaged or inoperativepositio-n, a portion of the view being in cross section and Figure 1 is a section on the line 88 of Figure 2.

In-the embodimentv disclosed. herein, I have shown myi-nvention as applied to athread- .ing machine ofthat type in whiclrthework the:stock1,the disengaged or inoperative posi- -tion of-the parts being-shown-inFigure 3 of is rotated and the thread cutting member is held stationary. -It is to be understood,

however, that my invention is equally applicable to other types ofmachines. Figure 1 of-the 'drawings discloses a base 10 on which J" the threadi'ng machine, indicated generally at 11,an(:l-the-fa'cing or cutting oif mechanism,

indicated-at 12, are mounted. F The stoclror pipe 13 is inserted'from the left-hand-endof "thethreading machine and is gripped' by a prises a supporting member-16 and a sectional threading member, 18,; the lastmentioned member comprisingtWo-sections 19- and 20.

'lhese sections are pivotally mountedat22 on the support 16 and serve to support the thread cuttingelements 21,- which are commonly knownv as chasingtools. It-Willthus beseen that the sections 19 and maybe separated to disengage the chasing tools from the drawings. 1 An abutment 24 is providedon the-section 20 and a cooperating abutment 25 is screwthreaded into afportion of the section 19 forlimitingthe movement ofthe sections to-work engaging position. The abutment 25" may be adj usted to accurately determine the proper position oft-he parts during the threading operation.

The power actuatedmechanismfor controlling the pivotal movement of the sections 19 and 20=may beconstructed in various ways,

butpreferably comprises a pair-0f bell crank levers 27 and'28 whichmay be mounted on anyconvenient portion of the supporting member 16 and which areconnected by a link 29.' The opposite arms of these bell crank levers are adjustably connectedvvith respective sections of the threadingmember; one of'these adjustable connections being shown at 30. The connection between the remain- .ing bell .cranklever and the corresponding section comprises a rod 31 which is threaded into the bell crank leveratone end an'd is provided witha headedportion 32 at 1ts opposite end for cooperation with a member 33 formed on the section 19. An element 3 1 threaded on rod 31 serves as an adjustable abutment for a spring 35. At its opposite end this spring engages a sleeve 36 which is in turn in contact with the member 33.

In Figure 3 these parts are shown in the positions which they occupy when the thread cutting elements are disengaged from the stock and it will be observed that the spring 35 maintains the member in engagement with the headed portion 32 of the rod 31. The

vspring 35 is sufliciently stiff to resist any movement of the thread cutting elements during the cutting operation and serves to retain these cutting elements firmly in engagement with the stock. It will nevertheless be observed by reference to Figure 2, in which the cutting elements are illustrated in the position which they occupy during the cutting operation, that the spring 35 is permitted to yield slightly when the sections 19 and 20 of the threading member 18 occupy their closed position. For instance, the abutment is preferably so adjusted as to seat firmly against the abutment 2 1 in the closed position of the threading member, these two abutments engaging slightly before the bell crank levers 27 and 28 have completed their move- .ment to engage the cutting elements with the stock. This movement results in a slight compression of the spring so that as shown in Figure 2, there is a slight clearance between the member 33 and the headed portion 32 on the rod 31.

It is essential that some yieldable element be provided in the train of actuating mechanism for the sections of the threading memher since ordinary wear between the various moving parts and even slight changes in the length of these parts due to variations in temperature would otherwise render it impossible to properly engage the cooperating abutments 24 and 25. These difiiculties are overcome in the present instance by the slight yielding of the spring 35 after the abutments engage, but it will be understood that this spring is preferably of such strength as to prevent further compression thereof during the actual cutting operation.

In the embodiment of the invention illustrated in the drawings the bell crank levers 27 and 28 are simultaneously actuated by means of a link 36 pivoted to one arm of the lever 27. This link is preferably provided with an adjustable connection indicated at 36 with a piston rod 37 w rich is in turn reciprocated by a fluid operated device 38 mounted on the supporting member 16.

Operation of the device 38 thus .erves to rock the bell crank levers Q7 and 28 to effect simultaneous movement of the sections 19 and 20 of the threading member about their point of pivotal support 22.

WVhile this arrangement ensures effective and prompt manipulation of the sections of the threading member to operative and inoperative positions, it will be understood that power mechanism such as illustrated in the drawings need not be used to operate the bell crank levers 27 and 28 since these levers may be operated manually if desired by providing any conventional form of hand control therefor. In either event the threading member 18 may be rapidly moved to operative and inoperative positions by means of the linkage which provides in effect a toggle action as distinguished from arrangements in which threaded mechanism requiring considerable manipulation for the closing and opening of the threading member is employed. This saving of time in the operation of the threading member is small when only one such operation is considered but in the modern high speed threading machine it becomes tremendously important during the operation of the machine over long periods of time.

Since it is important to maintain the sections 19 and 20 in accurate alignment, and since these sections are subject to frequent movement during the operation of the machine, it has been found necessary to provide means for assuring the retention of the sections in their proper ilane of movement. The invention therefore contemplates the provision of means for maintaining the side faces of the sections 19 and 20 in engagement with the member 16 over a substantial portion of the surface thereof regardless of the position of the sections. One such means is illustrated in the drawings, and comprises plates 40 and 41 located on each side of the zone of operation of the cl asing tools. Figure 4; shows a cross-section taken through the plate 410, from which it will be seen that this plate is mounted on the member 16 by means of shouldered bolts 43 for sparing the plate 10 a sufficient distance from the member 16 to accommodate the sections 19 and 20 therebetwecn. It is obvious that the spacing between these parts might be so designed as to maintain the sections 19 and 20 in close working engagement with both the plate 40 and the supporting member 16. Under these conditions, however, the wear between the parts due to the frequent opening and closing of the sections soon results in an undesirable amount of clearance so that the sections of the threading member are not held in close alignment, causing improper cutting or mutilation of the threads. This difficulty is overcome in the present invention by the provision of bearing members 4-2 which are slidably mounted in the plate 10 and are actuated by springs 44: into engagement with the side faces of the sections 19 and 20, thus retaining these sections in close engagement with the supporting member 16. Since the spring pressed bearing members are located at spaced points on each side of the chasing tools, the sections 19 and 20 are maintained in proper working relation-j;

. support.

ship regardless of wear.

VVh1le I have described one embodiment of my invention for the purpose of illustrating the principles and mode of operation involved, it will be appreciated that various changes and alterations may be made in the 1 details of construction specifically shown and 1 described and that such further modifications are contemplated as fall within the spirit and .1. In threading apparatus, the combinatlon with a support, of a pair of COOPQI'ELUHQ die sections pivotally mounted thereon for movement into and out of work engaging position, and means for moving said die sections comprising a pair of bell crank levers pivotally mounted on said support, means for actuating one of said levers, a link connection between one arm of each lever, and a connection between each of the other arms and one of said die sections.

2. In threading apparatus, the combination with a support, of a pair of cooperating die sections pivotally mounted thereon for movement into and out of work engaging position, and means for moving said die sections comprising a pair of bell crank levers pivotally mounted on said support, means for actuating one of said levers, a link connection between one arm of each vlev r, and a connection be tween each of the other arms and one of said dissections, one of said last mentioned connections being resilient. A

3. In threading apparatus, the combination witha support,oi' a pair of cooperating die sections pivotally mounted thereon for movement into and out of Work engaging position, relatively adjustabie cooperating abutments on said die sections for limiting the movement thereof to work engaging position, and means for moving said die sections comprising a pair of bell crank levers pivotally mounted on said support, means for actuating one of said levers, a linkconnection between one armof each lever, and av connection between each of the other arms and one of said die sections.

at. In threading apparatus, the combination with a support, of a pair of cooperating die sections pivotally mounted thereon for movement into and out of work engaging position, and resilient means engaging each die section to retain the latter in engagement with said support for preventing dis alignment of said sections.

5. In threading apparatus, the combination with a support, of a pair of cooperating die sections pivotally mounted thereon, each section having a side face bearing against said support, and resilient means engaging the opposite side face of eachsection for main support.

taming said sectionsiin engagement withsi id 6. In threading apparatus, the combination witha support, of a pair of. cooperating die sections pivotally mounted thereon, ea'ch SQCtlOIl having a SlClG jfacebearing agalnst said support, and resilient. means carried by said support and engaging the, oppositeside face of each section or maintaining; said sections in engagement withsaid support.

7. In; threading apparatus, the-combinationwith a support, of a pair of cooperating die sections pivotally mounted thereon,=-eac h section having-a slde face bearlngfagainst said support,a platemounted onsaidsup- 'o port and located, adjacent the oppositeside faces of. the sections, and yielding means .mounted on saidplate andengagingsaid sections to hold them in engagement with said 8. In threading apparatus, the combination with a support, of a pair of cooperating die sections pivotally-mounted thereon, each section having a slde face bearing against said support, a plate mounted on said sup-:- e0

port and located adjacent the opposite'side faces of the sections, a member for engage ment with each die section mounted in said plate, and a spring for urging each member outwardly from said plate to maintain thec,;

sections in engagement with said support.

9. In threading apparatus, the combination with a support, of a pair of cooperating die sections pivotally mounted thereon, each section having a work engaging portion inter- 2100 mediate the ends thereof, andresilient means mounted on each side of said intermediate portions for maintaining said sections in engagement with said support to prevent dis- 7 alignment of the sections. 1 10. In threading apparatus, the combination with a support, of a pair of cooperating die sections pivotally mounted thereon for movement into and out of work engaging )osition means carried b said sections and-.,-11o

arranged to engage to limit the movement of said die sections into work engaging position, and mechanism operable to move said die sections toward and from each other, said mechanism including an element adaptedto llo yield in response to continued operation of said mechanism after said means have engaged.

11. In threading apparatus, the combination with a support of a pair of cooperating;;;12o

die sections pivotally mounted thereon for movement into and out of work engaging position, cooperating abutments associated with said die sections arranged to engage to limit the movement of the sections to work 11 engaging position, one of saidabutments being ustable to vary the relative position other, saidmechanism including an elementi j fi I is adapted to yield in response to continued operation of said mechanism after said abutments have engaged.

12. In threading apparatus, the combination with a support, of a pair of cooperating die sections pivotally mounted thereon for movement into and out of Work engaging position, means carried by said sections and arranged to engage to limit the movement of said die sections into Work engaging position, and mechanism operable to move said die sections toward and from each other, said mechanism including a spring adapted to yield in response to continued operation of said mechanism after said means have engaged, said spring oiiering sufiicient resistance to deflection to firmly retain said means in engagement during the threading operation. In testimony whereof I hereunto aflix my signature.

ERIK W. MIKAELSON. 

